SigmaStat is a statistical software package, which was originally developed by Jandel Scientific Software in the 1980s. As of October 1996, Systat Software is now based in San Jose, California. SigmaStat users have the ability to compare effects among groups. This includes before and after or repeated measure studies. The users can also conduct survival analysis, analyze rates and proportions, perform regression and correlation analysis and calculate power and sample size. The program uses a wizard based interface which asks the user questions about the project and its data. After a test is run, the user receives a detailed report that interprets the results.

If installed with SigmaPlot, SigmaStat integrated with SigmaPlot and SigmaPlot gained advanced statistical analysis capabilities in recent versions of both software (SigmaStat 3 and SigmaPlot 10). Now SigmaStat is no longer continued as a separate product but integrated with SigmaPlot after version 11.